Horizontal pumps, refill units and foam dispensers with integral air compressors

ABSTRACT

Foam dispensers having integral air compressors with connectors to connect with a disposable refill unit, disposable refill units and liquid pumps are disclosed herein. A refill unit includes a container and a liquid pump. The liquid pump includes a liquid chamber defined at least in part by a liquid inlet valve and a liquid outlet valve. A piston that reciprocates horizontally in the liquid chamber. A mixing chamber is located downstream of the liquid chamber. The mixing chamber is in fluid communication with the liquid chamber and has an air inlet. A sanitary seal is located proximate the air inlet to prevent liquid from contaminating the air compressors.

RELATED APPLICATIONS

This non-provisional utility patent application claims priority to andthe benefits of U.S. Provisional Patent Application Ser. No. 61/692,290filed on Aug. 23, 2012, and entitled HORIZONTAL PUMPS, REFILL UNITS ANDFOAM DISPENSERS WITH INTEGRAL AIR COMPRESSORS. This application isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates generally to liquid pumps, refill unitsfor foam dispensers and foam dispenser systems, and more particularly tohorizontal liquid pumps, refill units and foam dispensers havingintegral air compressors.

BACKGROUND OF THE INVENTION

Liquid dispenser systems, such as liquid soap and sanitizer dispensers,provide a user with a predetermined amount of liquid upon actuation ofthe dispenser. In addition, it is sometimes desirable to dispense theliquid in the form of foam by, for example, injecting air into theliquid to create a foamy mixture of liquid and air bubbles. As a generalmatter, it is usually preferable to reduce the space taken up by thepumping and foaming apparatus within the overall dispenser system. Thismaximizes the available space for storing the liquid, and has otherbenefits.

SUMMARY

Pumps, foam refill units and foam dispenser systems are disclosedherein. Embodiments of disposable refill units for foam dispensers thathave an integral air compressor are provided. One embodiment includes acontainer and a liquid pump. The liquid pump includes a liquid chamberdefined at least in part by a liquid inlet valve and a liquid outletvalve. A piston reciprocates horizontally in the liquid chamber. Amixing chamber is located downstream of the liquid chamber. The mixingchamber is in fluid communication with the liquid chamber and has an airinlet. A sanitary seal is located proximate the air inlet to allow airto enter the mixing chamber and prevent liquid from exiting the mixingchamber through the air inlet

Another embodiment of a disposable refill unit for a foam dispenser isdisclosed that has an integral air compressor and includes a containerand a liquid pump. The liquid pump has a liquid chamber defined at leastin part by a liquid inlet valve and a liquid outlet valve. A mixingchamber is located downstream of the liquid chamber. The mixing chamberincludes an air inlet and a sanitary seal located proximate the airinlet. The sanitary seal allows air to enter the mixing chamber andprevents liquid from exiting the mixing chamber through the air inlet.The container, the liquid pump and the sanitary seal are disposablewithout disposing of the air compressor.

Embodiments of foam dispensers for receiving replaceable refill unitsare also disclosed. One embodiment of a foam dispenser includes ahousing, an actuator and an air compressor. In addition, the dispenserincludes a connector that releasably connects the air compressor to anair inlet on a disposable refill unit when the disposable refill unit isinstalled in the foam dispenser and disconnects from the disposablerefill unit when the refill unit is removed. The actuator is configuredto move horizontally and actuate the air compressor. In addition, arefill unit mounting bracket is included to receive and releasablyretain a replaceable refill unit.

In addition, pumps and refill units having a novel liquid inlet valveare also disclosed herein. In one embodiment, a refill unit includes acontainer of foamable liquid and a pump secured to the container. Thepump includes a pump housing having a first aperture therethrough. Aliquid inlet valve is provided through the first aperture. The pump alsoincludes one or more liquid inlet passages through the housing. Theliquid inlet valve includes a stem portion. The stem portion includes aprojection member on one end and a sealing member on the other. Theprojection member fits through the aperture from outside of the pumphousing and the sealing member is located upstream of the one or moreliquid inlets.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention willbecome better understood with regard to the following description andaccompanying drawings in which:

FIG. 1 illustrates a dispenser system 100 having an air compressor 150attached thereto and a refill unit 110 installed therein.

FIG. 2 illustrates a prospective view of the generic dispenser 101having an air compressor 150 attached thereto;

FIG. 3 illustrates a cross-section of an exemplary embodiment of arefill unit 110 for use in a dispenser system 100 showing a portion of acontainer 112 for holding a fluid and a liquid pump 120;

FIG. 4 illustrates a cross-section of an exemplary embodiment of arefill unit 110 installed in a dispenser 100 and mated with aircompressor 150;

FIG. 5 illustrates another exemplary embodiment dispenser system 500with a refill unit 510 installed therein;

FIG. 6 illustrates a cross-section of an exemplary embodiment of thedispenser 500 for use in a dispenser system 500 that includes an aircompressor 550 secured thereto;

FIG. 7 illustrates a plan view of an exemplary embodiment of an aircompressor 550 for use in a dispenser system 500;

FIG. 8 illustrates a cross-section of an exemplary embodiment of arefill unit 510 including a container 512 and liquid pump 520;

FIG. 9 illustrates a cross-section of an exemplary embodiment of therefill unit 510 installed in a dispenser 501 mated with air compressor550;

FIG. 10 illustrates a cross-section of an exemplary embodiment of a pump1000 for use in a refill unit of a foam dispenser in a dischargedposition;

FIG. 11 illustrates a cross-section of the exemplary embodiment of apump 1000 for use in a refill unit of a foam dispenser in a chargedposition; and

FIG. 12 illustrates a cross-section of another exemplary pump 1200.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary embodiment of a foam dispensing system100 with a side of the housing being transparent. Foam dispensing system100 includes a disposable refill unit 110 installed in a foam dispenser101. The disposable refill unit 110 includes a container 112 connectedto a liquid pump 120. Liquid pump 120 includes an air inlet 124. Thedisposable refill unit 110 may be placed within housing 102 of thedispenser 101 and releasably placed in fluid communication with aircompressor 150. The term air compressor is used interchangeably hereinwith the term “air pump.”

The foam dispenser system 100 may be a wall-mounted system, acounter-mounted system, an un-mounted portable system movable from placeto place or any other kind of foam dispenser system. Foam dispenser 101includes an air compressor 150 secured thereto. Air compressor 150 maybe permanently mounted to foam dispenser 101. Air compressor 150includes a conduit or air passage 152, with a connector 154 forreleasably connecting to the air inlet 124 of liquid pump 120.Optionally, connector 154 may be secured to pump 120. In one embodiment,connector 154 is a two-part connector, and one part is connected to pump120 and the other to air passage 152. In one embodiment, the connector154 is made up of a male fitting on one of the liquid pump air inlet 124or the air passage 152 of air compressor 150 and a female fitting on theother. Accordingly, refill unit 110 and pump 120 may be removed fromdispenser housing 102 and discarded without removal of the aircompressor 150. Connector 154 may be a quick-release connector, areleasable snap-fit connector, a releasable compression-fit connector, aslip-fit connector or a sealing member such as, for example, a foam orflexible member that compresses to form a seal between air passage 152and pump 120. The air compressor 150 may be any type of air compressorsuch as, for example, a compressible bellows, a rotary air compressor, apiston air compressor, a fan, a compressor, a positive displacement pumpor the like.

The container 112 forms a liquid reservoir 114. The liquid reservoir 114contains a supply of a foamable liquid within the disposable refill unit110. In various embodiments, the contained liquid could be for example asoap, a sanitizer, a cleanser, a disinfectant or some other foamableliquid. In the exemplary disposable refill unit 110, the liquidreservoir 114 is formed by a collapsible container 112, such as acontainer made of thin plastic or a flexible bag-like container. Inother embodiments, the liquid reservoir 114 may be formed by a rigidhousing member, or have any other suitable configuration for containingthe foamable liquid without leaking. The container 112 mayadvantageously be refillable, replaceable or both refillable andreplaceable. In other embodiments, the container 112 may be neitherrefillable nor replaceable.

In the event the liquid stored in the reservoir 114 of the installeddisposable refill unit 110 runs out, or the installed refill unit 110otherwise has a failure, the installed refill unit 110 may be removedfrom the foam dispenser system 100. The empty or failed disposablerefill unit 110 may then be replaced with a new disposable refill unit110 including a liquid-filled reservoir 114. The air compressor 150remains located within the foam dispenser 101 while the disposablerefill unit 110 is replaced. In one embodiment, the air compressor 150is also removable from the housing 102 of the dispenser 101, separatelyfrom the disposable refill unit 110, so that the air compressor 150 maybe replaced without replacing the dispenser 101, or alternatively tofacilitate removal and connection to the refill unit 110. As describedin more detail below, sanitary sealing may be used to isolate the aircompressor 150 from the portions of the liquid pump 120 that contactliquid, so that the air compressor 150 mechanism does not contact liquidduring operation of the foam dispenser system 100.

The housing 102 of the dispenser 101 further contains one or moreactuating members 104 to activate the liquid pump 120 and air compressor150. As used herein, actuator or actuating mechanism includes one ormore parts that cause the dispenser 101 to move liquid, air or foam.Actuator 104 is generically illustrated because there are many differentkinds of pump actuators which may be employed in the foam dispensersystem 100. The actuator of the foam dispenser system 100 may be anytype of actuator such as, for example, a manual lever, a manual pullbar, a manual push bar, a manual rotatable crank, an electricallyactivated actuator or other means for actuating the liquid pump 120 andair compressor 150 within the foam dispenser system 100. Electronicactuators may additionally include a sensor to provide for a hands-freedispenser system with touchless operation. Various intermediate linkagesconnect the actuator member 104 to the pump 120 and or air compressor150 within the system housing 102.

The exemplary liquid pump 120 and air compressor 150 are horizontalpumps. That is, the pumps are actuated by a substantially horizontalmovement. The external actuator 104 may be operated in any manner, solong as the intermediate linkages transform that motion to asubstantially horizontal motion to activate the liquid pump 120 and aircompressor 150. As illustrated, dispenser 101 includes a manual actuatorlever 104 that is secured to housing 102 by a hinge 103. In oneembodiment, actuator lever 104 includes a pivotal contact element 105that contacts actuator arm 156 to activate the pump 120 and aircompressor 150. Pump 120 includes a dispensing nozzle 122 which extendsbelow the bottom of housing 102. In addition, a refill retaining bracket180 is secured to housing 102. Refill retaining bracket 180 releasablyretains the refill unit 110 in foam dispenser 101. Refill unit 110,including the liquid pump 120 and outlet nozzle 122 may be readilyinserted and removed from foam dispenser 101 without removing the aircompressor 150 from the foam dispenser. Accordingly, all of the elementsthat contact liquid, “wet parts,” may be disposed of without the need todispose of components that do not contact liquid.

FIG. 2 illustrates a prospective view of an embodiment of dispenser 101.Dispenser 101 includes a housing 102, which is illustrated astransparent for purposes of clairity. Housing 102 includes a frontportion 205 that is attached by hinge 203. Front portion 205 of housing102 rotates down to facilitate inserting a refill unit (not shown) intodispenser 101. As discussed with respect to FIG. 1, front portion 205 ofhousing 102 includes an actuator lever 104. Housing 102 includes anopening 220 in the bottom thereof which allows nozzle 122 to dispensefoam to an object located below dispenser 101. Secured to housing 102 isair compressor 150.

In one embodiment, air compressor 150 includes a cylinder 208. Cylinder208 includes a side wall and a bottom wall. A piston 206 fits withincylinder 208 and sealing member 401 (FIG. 4) creates a seal between theoutside wall of piston 206 and the inside wall of cylinder 208. Securedto piston 206 is an actuator arm 156. Actuator arm 156 includes a pairof extensions 202, which are linked to cross member 204. Air compressor150 also includes air compressor outlet 152 that releasably engages withliquid pump 120. In one embodiment, air compressor 150 includes an airinlet 404 (FIG. 4) and one-way air inlet valve 406. One-way air inletvalve 406 allows air to enter air compressor 150 to recharge the airchamber 410. In addition, in one embodiment, air compressor 150 includesa biasing member 402 to move the piston 206 to its outermost positionand recharge the air chamber 410.

FIG. 3 illustrates a cross-section of an exemplary embodiment of arefill unit 110 that includes pump 120 and container 112. Container 112includes a neck portion 302. Pump 120 is connected to the neck 302 ofcontainer 112 by a press fit connection. Optionally, a cap (not shown)may connect pump 120 to container 112. Still yet, other means such as,for example, a compression fit, welding, adhesive, friction fit, etc.may be used to join pump 120 with container 112.

Pump 120 includes a pump housing 306 that contains a liquid chamber 320.Pump housing 306 includes an inlet opening 312. A one-way liquid inletvalve 314 is located in the inlet opening 312. The upper portion ofliquid inlet valve 314 includes slots (not shown) for liquid to passthrough and flow into inlet opening 312. Optionally, additional liquidinlet openings may be provided. One-way liquid inlet valve 314 may beany type of valve such as, for example, a flapper valve, a conicalvalve, a plug valve, an umbrella valve, a duck-bill valve, a slit valve,a mushroom valve or the like. One-way liquid inlet valve 314 allowsliquid to flow into liquid chamber 320 and prevents liquid from flowingout of liquid chamber 320 back into container 112. Pump housing 306includes a liquid outlet opening 330 that has a one-way liquid outletvalve 332 associated therewith. One-way liquid outlet valve 332 may beany type of valve such as, for example, a flapper valve, a conicalvalve, a plug valve, an umbrella valve, a duck-bill valve, a slit valveor a mushroom valve, so long as it opens under pressure to allow liquidto exit the liquid chamber 320, but does not let air, liquid or foamenter the liquid chamber 320 through opening 330.

Located at least partially within liquid chamber 320 is a sleeve 324.The sleeve allows the pump housing 306 to be cheaply manufacturedwithout tight tolerances and even have dips or recesses in the pumpchamber. In some embodiments, the pump housing 306 has unevencross-section, uneven fill. The sleeve is made with more precision andhas tighter tolerances and is inserted into the pump chamber 320. Aliquid tight seal prevents liquid from flowing out of liquid chamber 320around sleeve 324 and out of pump 120 and secures sleeve 324 to pumphousing 306. The liquid tight seal may be formed by having end cap 358of sleeve 324 fit snuggly within liquid chamber 320 near the one end.End cap 358 seals the opening and retains piston 350. Optionally, endcap 358 may be secured to the housing 306 by an adhesive, by welding orthe like.

A passageway 360 exists between the outside of sleeve 324 and the insidewall of liquid chamber 320. The passageway 360 allows liquid to flowinto and out of the liquid chamber 320, which includes the interior ofsleeve 324. Sleeve 324 may be cylindrical or may have outwardlyextending ribs to engage the wall of the liquid chamber 320. Ribs (notshown) may facilitate the creation of multiple passageways 360 in theopen areas created by the ribs.

Sleeve 324 allows inlet valve 314 and outlet valve 332 to be placedalong any point of liquid chamber 320. Accordingly, the liquid inletopening 312 and liquid outlet opening 330 may be advantageouslypositioned. In addition, piston head 352 may travel past inlet valve 314and outlet valve 332. For example, in one embodiment, the liquid outletopening 330 is located near the front of the refill unit 110 so that thefoam may be dispensed at location that is further away from the back ofthe dispenser 100. In one embodiment, the liquid inlet opening 312 islocated near the front of the refill unit 101. This flexibility allowsthe pump 120 to be easily modified for different applications. It alsoallows for flexibility in the design of the container 112. For example,the neck 302 of the container 112 may be located towards the front ofthe refill unit 110 rather than in the center of the refill unit 110. Insome embodiments, the liquid inlet opening 312 and liquid outlet opening330 are offset from one another. In one embodiment, the liquid outletopening 330 is located closer to the front of the refill unit 110 thanthe liquid inlet opening 312. In one embodiment, sleeve 324 is notrequired; however, in that embodiment, the liquid inlet and liquidoutlets are located so that the stroke of the piston 360 does not causepiston head 352 to pass the liquid inlet 312 and liquid outlet 330during operation.

In the embodiment illustrated in FIG. 1 the inlet and outlet valves 314,332 are aligned on a centerline of the container 112. In one embodiment,one or both of the inlet and outlet valves 314, 332 are located off ofthe centerline of the container 112. In another embodiment, both theinlet and outlet valves 314, 332 are located off of the centerline ofthe container 112. One or both may be located closer to the front of thecontainer. In such embodiments, the neck 302 of the container 112 mayalso be offset from the centerline of the container 112. In oneembodiment, the neck 302 of the container 112 is offset towards thefront of the container. As used herein, “offset from the centerline ofthe container” means that the object is offset from at least onecenterline, not necessarily from all potential centerlines of thecontainer.

Pump 120 includes a liquid piston 350. Liquid piston 350 has a pistonhead 352 that has a liquid piston seal 356. Liquid piston seal 356 maybe any type of seal such as, for example, a wiper seal, an o-ring, agasket or the like. Liquid piston seal 356 engages the inside wall ofsleeve 324. Preferably, liquid piston seal 356 has enough contactagainst sleeve 324 so that liquid does not pass by the seal, but thecontact is limited so that less energy is necessary to move the piston350. Pump 120 may include a biasing member (not shown) to move piston350 outward when no horizontal force is being applied to the piston 350.Optionally, piston 350 may have an engagement member (not shown) thatengages with actuator arm 156 to move piston 350 to its outermostposition, when no force is being applied to the actuator arm 156.

Pump housing 306 includes mixing chamber 336 located downstream ofoutlet opening 330. As fluid passes by one-way outlet valve 332, itenters mixing chamber 336. Mixing chamber 336 includes an air inlet 124.In some embodiments, air inlet 124 includes a one-way valve 338. One-wayvalve 338 may be any type of one-way valve such as, for example, thoseidentified above. One-way inlet valve 338 is a sanitary valve in that itprevents liquid or foam from traveling past and contaminating aircompressor 150 or other parts that remain with the dispenser 101 whenthe refill unit 110 is removed from the dispenser 101. It is desirableto keep the parts that remain with the dispenser 101 free fromcontamination with the liquid or fluid to prevent bacteria from growingin the dispenser 101. Thus, a user need only replace the refill unit 110including the wet parts without the need for replacing the aircompressor 150.

In some embodiments, the air pump(s) or air compressor(s) disclosedherein include an air inlet having a one-way air inlet valvetherethrough. The one-way air inlet valve allows air to enter the airpump to recharge the air pump. In some embodiments, the air inlet islocated inside of the foam dispenser housing so that air from inside ofthe dispenser is used to feed the air pump. Using air from inside thedispenser may help to prevent moisture from entering the air pumpthrough the air inlet and air inlet valve. In some embodiments, a vaporbarrier is provided at the air inlet. A vapor barrier allows air to passthrough the air inlet and enter the air pump, but prevents moisture fromentering the air pump. A suitable vapor barrier is a woven one-way vaporbarrier such as, for example, Gortex®, that is arranged so that vapordoes not enter the air pump.

In some embodiments, the air pump(s) or air compressor(s) include anantimicrobial substance molded into their housing. One suitableantimicrobial substance contains silver ions and/or copper ions. Asilver refractory, such as, for example, a glass, oxide or silverphosphate may be used. One suitable commercially available product isUltra-Fresh, SA-18, available from Thomson Research Associates, Inc.Other suitable antimicrobial materials that may be used in the air pumpinclude, but are not limited to Vinyzene™, available from the DowChemical Company, and Bisafe, a silane-based antimicrobial productavailable from the RTP Company. The antimicrobial substance preventsmold or bacteria from growing inside of the air pump or air compressor.Optionally several different types of antimicrobial substances may beused alone or in combinations with other antimicrobial substances, suchas for example, a combination of a leaching antimicrobial and anon-leaching antimicrobial. Suitable leaching antimicrobials mayinclude, for example, silver, nanosilver or copper may be used. Suitablenon-leaching antimicrobials include, for example, silver based andtriclosan based antimicrobials. Silver, copper, combinations of silverand copper alone, combinations of silver, copper and otherantimicrobials may be used. The use of the terms silver and copper usedherein are not intended to limit the types of copper or silver to metal,and is intended to cover metal salts and other variants of copper andsilver.

Downstream of mixing chamber 336 is a foaming cartridge 340. In oneembodiment, foaming cartridge 340 has a housing with one or more screenslocated therein. Optionally, foaming cartridge 340 may be replaced withone or more screens, a sponge or other porous member. In addition,secured to pump housing 306 is outlet nozzle 122.

As can be seen from the Figures, pump 120 is compact. The narrowerdiameter of liquid chamber 320 is more efficient in that it takes lessenergy to move a given volume of fluid than a larger diameter liquidchamber having the same volume but a larger diameter. Using less energyallows for a longer battery life for an electronic dispenser. Inaddition, the compact profile reduces shipping costs. Further, theability to reuse the air compressor provides sustainability and is“green” in that it reduces the amount of plastic that ends up inlandfills.

FIG. 4 illustrates refill unit 110 installed in dispenser housing 102and pump 120 is releasably mated with air compressor 150. To install therefill unit 110, the dispenser housing 102 is opened up and the refillunit 110 is lowered downward. As the refill unit 110 is lowered, theliquid pump air inlet 124 aligns with the air compressor outlet 152. Inone embodiment, as the two components align the refill unit 110 ispushed toward the back of the dispenser, the liquid pump air inlet 124slides into air compressor outlet 152 and is snug enough to form a seal.In addition, piston 350 fits within actuator arm 156 so that crossmember 204 will engage piston 350 when actuator lever 104 is movedhorizontally.

During operation, the foam dispensing system 100 is activated by movingactuator lever 104. Actuator lever 104 causes liquid piston 350 and airpiston 206 to move horizontally toward the rear of the foam dispensingsystem 100. Movement of liquid piston 350 horizontally reduces thevolume of liquid chamber 320. Once the pressure is sufficient toovercome the cracking pressure of liquid outlet valve 332, thepressurized liquid flows through passage 360 through passage 330, pastliquid outlet valve 332 and travels into mixing chamber 336. Movement ofair piston 206 reduces the volume of the air chamber 410 and pressurizesthe air in the air chamber 410. The pressurized air passes through aircompressor outlet 152, past sanitary valve 338, through liquid pump airinlet 124 and mixes with the liquid in mixing chamber 336 to form aliquid/air mixture. The liquid/air mixture is forced through foamingcartridge 340 and is dispensed through nozzle 122 as a foam.

Upon release of actuator lever 104, the biasing member 402 in the aircompressor 150 urges air piston 206 away from the rear of dispensersystem 100 and expands the volume of air chamber 410. Sanitary valve 338prevents air from entering the air chamber 410 through the aircompressor outlet 152. Accordingly, air is drawn into air chamber 410through air inlet 404 past one-way air inlet valve 406. In addition,liquid piston 330 is urged outward away from the rear of the dispensersystem 100. As liquid piston 330 moves outward, liquid chamber 320expands creating a vacuum. The vacuum pressure seals liquid outlet valve330 and once the vacuum pressure is sufficient to overcome the crackingpressure of liquid inlet valve 314, liquid flows from container 112 pastliquid inlet valve 314 through the passage 360 and into liquid chamber320. The pump 120 and air compressor 150 are now primed and ready forthe next dispense cycle.

FIG. 5 illustrates another exemplary embodiment of a foam dispensingsystem 500. Foam dispensing system 500 includes a disposable refill unit510 for use in a foam dispenser 501. The disposable refill unit 510includes a container 512 connected to a liquid pump 520. Liquid pump 520includes an air inlet 824 (FIG. 8). The disposable refill unit 510 maybe placed within a housing 502 of the dispenser 501 and releasablyplaced in fluid communication with an air compressor 550. The foamdispenser system 500 may be a wall-mounted system, a counter-mountedsystem, an un-mounted portable system movable from place to place or anyother kind of foam dispenser system. Foam dispenser 501 includes an aircompressor 550 secured thereto (see FIG. 6). Air compressor 550 may bepermanently mounted to foam dispenser 501. Air compressor 550 includes aconduit or air passage 620 (FIG. 6), with an annular receptacle 554 forreleasably connecting to the air inlet 824 of liquid pump 520. Thereleasable connection is achieved by sliding a portion of the liquidpump 520 into annular receptacle 554. Accordingly, refill unit 510 andpump 520 may be removed from dispenser housing 502 and discarded withoutremoval of the air compressor 550. Air compressor 550 is a dual pistonair compressor; however, the air compressor 550 may be any type of aircompressor such as, for example, a bellows air compressor, a rotary aircompressor, a piston air compressor, a fan, a compressor, a blower orthe like. It may be a single air compressor or may be multiple aircompressors.

The container 512 forms a liquid reservoir 514. The liquid reservoir 514contains a supply of a foamable liquid within the disposable refill unit510. In various embodiments, the contained liquid could be for example asoap, a sanitizer, a cleanser, a disinfectant or some other foamableliquid. In the exemplary disposable refill unit 510, the liquidreservoir 514 is formed by a collapsible container 512, such as aplastic container or a flexible bag-like container. In otherembodiments, the liquid reservoir 514 may be formed by a rigid housingmember, or have any other suitable configuration for containing thefoamable liquid without leaking. The container 512 may advantageously berefillable, replaceable or both refillable and replaceable. In otherembodiments, the container 512 may be neither refillable norreplaceable.

In the event the liquid stored in the reservoir 514 of the installeddisposable refill unit 510 runs out, or the installed refill unit 510otherwise has a failure, the installed refill unit 510 may be removedfrom the foam dispenser system 500. The empty or failed disposablerefill unit 510 may then be replaced with a new disposable refill unit510 including a liquid-filled reservoir 514. The air compressor 550remains located within the foam dispenser 501 while the disposablerefill unit 510 is replaced. In one embodiment, the air compressor 550is also removable from the housing 502 of the dispenser 501, separatelyfrom the disposable refill unit 510, so that the air compressor 550 maybe replaced without replacing the dispenser 501, or alternatively tofacilitate removal and connection to the refill unit 510. Optionally,air compressor 550 may be mounted to the liquid pump 520 and disposed ofalong with the refill unit 510. As described in more detail below,sanitary sealing may be used to isolate the air compressor 550 from theportions of the liquid pump 520 that contact liquid, so that the aircompressor 550 mechanism does not contact liquid during operation of thefoam dispenser system 500.

The housing 502 of the dispenser 501 further contains one or moreactuating members 504 to activate the pump 520 and air compressor 550.As used herein, actuator or actuating mechanism includes one or moreparts that cause the dispenser 501 to move liquid, air or foam. Thereare many different kinds of pump actuators which may be employed in thefoam dispenser system 500 such as, for example, a manual lever, a manualpull bar, a manual push bar, a manual rotatable crank, an electricallyactivated actuator or other means for actuating the liquid pump 520 andair compressor 550 within the foam dispenser system 500. Electronic pumpactuators may additionally include a sensor to provide for a hands-freedispenser system with touchless operation. Various intermediate linkagesconnect an actuator member to the pump 520 within the system housing502.

The exemplary liquid pump 520 and air compressor 550 are horizontalpumps. That is, they are actuated by a substantially horizontalmovement. The external actuator 504 may be operated in any manner, solong as the intermediate linkages transform that motion to asubstantially horizontal motion on the liquid piston 850 and air piston606. Dispenser 501 includes a manual actuator lever 504 that is securedto housing 502 by a hinge 503. In one embodiment, actuator lever 504includes pivotal contact elements 505, 506 that contact pistons 602 and850 respectively to activate the pump 520 and air compressor 550. Pump520 includes a dispensing nozzle 522 which extends below the bottom ofhousing 502. In addition, a refill retaining bracket 580 is secured tohousing 502. Refill retaining bracket 580 releasably retains the refillunit 510 in foam dispenser 501. Refill unit 510, including the liquidpump 520 and outlet nozzle 522, may be readily inserted by loweringrefill unit 510 into dispenser 501 and removed from foam dispenser 501by lifting upward without removing the air compressor 550 from the foamdispenser.

FIG. 6 illustrates a cross-section of the exemplary embodiment of foamdispenser 501 without a refill unit. Foam dispenser 501 includes housing502, actuator lever 504, liquid piston pivotal contact element 505, airpiston pivotal contact element 506 and air compressor 550 as discussedabove. Air compressor 550 is secured to housing 502. Air compressor 550is best understood with respect to FIGS. 6 and 7. Air compressor 550includes a pair of a cylindrical housings 604. Pistons 602 movereciprocally within piston housings 604. Pistons 602 include sealingmembers 603 that form a seal between pistons 602 and piston housings604. In one embodiment, biasing members 640 such as, for example,springs are located within cylindrical housings 604 to urge pistons 602to their outermost positions. Cylindrical housings 604 include airoutlets 620 and air inlets 641. One-way air inlet valves 643 areincluded in air inlets 641 to allow air into the cylindrical housings604 but prevent air from exiting through air inlets 641. Air outlets 620enter into annular receptacle 554. Annular receptacle 554 has an outsidewall 606, an inside wall 608 and a base 609. An opening 702 is providedin base 609 to allow the outlet nozzle 522 of liquid pump 550 to passthrough when the refill unit 510 is installed in dispenser 501.

FIG. 8 is a cross-sectional view of the exemplary embodiment of a refillunit 510. Refill unit 510 includes a container 512 and liquid pump 520secured thereto. Container 512 includes a neck portion 513 with annularprojections 806. Liquid pump 520 includes pump housing connector 808.Pump housing connector 808 includes an annular projection 811 that mateswith the annular projections 806 to connect pump 520 to container 512.Other types of connections may be used such, for example, as a press-fitconnection, a welded connection, an adhesive connection, a threadedconnection or the like. In addition, a sealing member (not shown) may beincluded between pump housing connector 808 and neck 513 to ensure aliquid tight connection between pump 520 and container 512.

Pump housing connector 808 is secured to pump housing 809. Pump housing809 may be a separate part from pump housing connector 808 or they maybe integrally formed. Pump housing 809 includes an aperture 812 that hasa one-way inlet valve 814 secured thereto. In one embodiment, one ormore liquid inlet apertures 813 are provided to allow liquid to flowfrom container 512 to liquid chamber 870. Optionally, the liquid mayenter through aperture 812. One-way liquid inlet valve 814 may be anytype of valve, such as for example, a flapper valve, a conical valve, aplug valve, an umbrella valve, a duck-bill valve, a slit valve or amushroom valve so long as it allows liquid to enter liquid chamber 870but prevents liquid from flowing from liquid chamber 870 back intocontainer 512.

Pump housing 809 includes an opening 872 through a sidewall. Opening 872leads to the interior of piston housing 858. Piston housing 858 is acylindrical housing that receives liquid piston 850. Liquid piston 850reciprocates back and forth in piston housing 858. Piston 850 includes aseal 856. Seal 856 may be any type of suitable seal such as, forexample, a wiper seal, one or more o-rings or the like. A biasing member859 such as, for example a spring may be included within piston housing858 to urge piston 850 to its outermost position to expand the volume ofliquid chamber 870.

Pump housing 809 includes connector 863. Connector 863 mates with nozzlehousing 860 to join the two together with a snap-fit connection. Othersuitable types of connections may be used such as, for example, apress-fit connection, an adhesive connection or the like. Nozzle housing860 includes a projecting member 861 that extends up into the interiorof pump housing 809. The connection between pump housing 809 and nozzlehousing 860 is a liquid tight connection, which is facilitated byannular groove 869 and sealing member 871. Nozzle housing 860 includesan aperture 830 therethrough with a one-way outlet valve 832 positionedtherein. One-way outlet valve 832 may be any type of valve such as, forexample, a flapper valve, a conical valve, a plug valve, an umbrellavalve, a duck-bill valve, a slit valve or a mushroom valve. One or moreapertures 833 allow liquid to pass through and into mixing chamber 880located in nozzle housing 860. Optionally, liquid may flow throughaperture 830. One-way outlet valve 832 allows liquid to exit liquidchamber 870 and flow into mixing chamber 880 located in outlet nozzlehousing 860 but prevents liquid, foam or air from moving from the mixingchamber 880 into liquid chamber 870. Downstream of mixing chamber 880 isa foaming cartridge 840. Foaming cartridge 840 may be include one ormore screens, a sponge or other obstructions to create a turbulentpathway through outlet nozzle housing 860 to cause the liquid and airmixture to form a rich foam. In one embodiment, foaming cartridge 840contains two or more screens. Downstream of foaming cartridge 840 isoutlet nozzle 882.

Nozzle housing 860 includes one or more openings 824 that lead fromoutside of the nozzle housing 860 into the mixing chamber 880. One-wayvalve(s) 825 are located proximate opening(s) 824 to provide a sanitaryseal between liquid pump 520 and air compressor 550 when the refill unit510 is installed in dispenser 501 (FIG. 9). One-way valve 825 may be anytype of valve such as, for example, a flapper valve, a conical valve, aplug valve, an umbrella valve, a duck-bill valve, a slit valve, amushroom valve or the like. One-way valve 825 prevents liquid and foamfrom coming in contact with the air compressor 550 or other componentsthat are not replaced with refill unit 510.

Nozzle housing 860 includes a pair of annular grooves 862 and 866. Apair of sealing members, such as, for example, o-rings 864 and 868 arelocated within grooves 862, 866 respectively. The o-rings 864, 868 forma seal with annular receptacle 554 when the refill unit 510 is placed infoam dispenser 501. The o-rings 864, 868 seal against inside wall 608(FIG. 6) of annular receptacle 554 and form an air passageway 910 thatplaces the liquid pump 520 in fluid communication with air compressor550 when the refill unit 510 is inserted into foam dispenser 501.Optionally, o-rings 864, 868 may be another type of sealing member, suchas, for example, a wiper seal, foam strip or the like.

Foam dispenser 501 may be permanently or semi-permanently installed in adesired location. Refill unit 510 is placed inside of dispenser 501 sothat nozzle housing 860 fits within annular receptacle 554 so thatsealing members 864, 868 form a sealed air passageway 910 to place themixing chamber 880 of nozzle housing 860 in fluid communication with aircompressor 550. One or more brackets 580 may be used to retain refillunit 510 in dispenser 501. The refill unit 510 is removed from dispenser501 by releasing bracket 580, or by lifting refill unit 510 upward.

During operation, the foam dispensing system 500 is activated by pushingactuator lever 504 which moves liquid piston 850 and air pistons 602horizontally toward the back of the dispenser. Movement of liquid piston850 horizontally reduces the volume of liquid chamber 870. Once thepressure is sufficient to overcome the cracking pressure of liquidoutlet valve 832, the liquid flows out of the liquid chamber 870 andtravels into mixing chamber 880. Movement of air piston 602 reduces thevolume of air chamber 642 and pressurizes the air in the air chamber642. The pressurized air passes through air compressor outlet 620 intopassageway 910 and into liquid pump air inlet 824 past sanitary valve825 and mixes with the liquid in mixing chamber 880 to form a liquid/airmixture. The liquid air mixture is forced through foaming cartridge 840and is dispensed through nozzle 522 as a foam.

Upon release of actuator lever 404, the biasing member 840 in the aircompressor 550 urges air pistons 602 away from the rear of dispensersystem 500 and expands the volume of air chamber 642. Sanitary valve 825prevents air from entering the air chamber 642 through the aircompressor outlet 620, and air is drawn into air chamber 642 through airinlet 641 past one-way air inlet valve 643. In addition, liquid piston850 is urged outward away from the rear of the dispenser system 500. Asliquid piston 850 moves outward, liquid chamber 870 expands creating avacuum. The vacuum pressure seals liquid outlet valve 832 and once thevacuum pressure is sufficient to overcome the cracking pressure ofliquid inlet valve 814, liquid flows from container 512 past liquidinlet valve 814 into liquid chamber 870. The pump 520 and air compressor550 are now primed and ready for the next dispense cycle.

FIGS. 10 and 11 are a cross-sectional view of an exemplary embodiment ofa pump 1000 suitable for use in foam dispensers and refill units forfoam dispensers. Pump 1000 includes a housing 1002. Housing 1002receives inlet plate 1008. Inlet plate 1008 includes a annularprojection 1006. A neck of a container (not shown) is received within anannular groove 1004 formed between annular projection 1006 and housing1002. Housing 1002 may be connected to the container by any means suchas, for example, a threaded connection, a welded connection, an adhesiveconnection or the like. Optionally, a gasket may fit in annular groove1004 to help form a liquid tight seal with the container. Inlet plate1008 may be integrally formed with housing 1002. Inlet plate 1008includes one or more inlet apertures 1009 located therethrough. Inaddition one-way inlet valve 1010 is secured to inlet plate 1008.One-way inlet valve 1010 may be any type of one-way valve such as, forexample, a ball and spring, a poppet valve, a flapper valve, an umbrellavalve, a slit valve or the like.

Pump housing 1002 includes a liquid chamber 1012. In one embodiment,liquid chamber 1012 is cylindrical. Located within liquid chamber 1012is a sleeve 1020. Housing 1002 includes an annular projection 1003 atone end of the liquid chamber 1012. Sleeve 1020 is secured to annularprojection 1003 by collar 1023. Collar 1023 includes an aperture 1025.Piston 1027 includes a shaft 1030 that projects through aperture 1025.Piston 1027 is slideable in a reciprocating manner within sleeve 1020.Piston 1027 includes a double wiper seal 1032 located at one end.Movement of piston 1027 causes the volume of liquid chamber 1012 toexpand and contract. Double wiper seal 1032 may be replaced with anytype of sealing member such as, for example, an o-ring, a single wiperseal or the like. Housing 1002 includes a projecting member 1034 thatcontacts an end 1033 of piston 1027 to stop movement of piston 1027 whenit reaches the end of its stroke.

An inlet passageway 1022 is formed between sleeve 1020 and the wall ofliquid chamber 1012. The inlet passageway 1022 may extend entirelyaround sleeve 1020 or may be enclosed by one or more rib projections(not shown) that cause liquid in inlet passageway 1022 to flow throughpassage 1024 into the interior of sleeve 1020. An outlet passageway 1026also exists between sleeve 1020 and liquid chamber 1012. The outletpassageway 1026 may extend entirely around sleeve 1020 or may beenclosed by one or more rib projections that cause liquid to flowthrough passage 1028 from the interior of sleeve 1020. Passageway 1022and passageway 1026 may be a common passageway.

Housing 1002 includes valve seat 1037. Connected to housing 1002 islower housing 1035. Lower housing 1035 may be connected to housing 1002by any means such as, for example, a threaded connection, a snap-fitconnection, a welded connection, an adhesive connection or the like.Lower housing 1035 has an interior cavity 1039. Lower housing 1035 alsoincludes a first annular projection 1040 that forms an air inlet 1042.An aperture 1044 connects air inlet to cavity 1039. Annular projection1040 may be releasably connected to an air source that is permanentlyconnected to a foam dispenser (not shown). The releasable connection maybe made by any means such as, for example, a snap-fit, friction fit, atube (not shown) that slides over or into annular projection 1040.

Lower housing 1035 also includes a second annular projection 1050 thathas a passageway 1052 connecting to cavity 1039. A compressible chambersuch as, for example, air bellows 1054 is connected to annularprojection 1050 by any means such as, for example, a friction fit, asnap fit, a welded connection, an adhesive connection or the like. Lowerhousing 1002 includes a floor 1071. A tapered section 1072 extends fromfloor 1071 to annular outlet 1074.

Located within cavity 1039 is an insert 1073. Insert 1073 may be made ofone or more components. Insert 1073 includes an interior cavity 1046formed by annular member 1075. Interior cavity 1046 retains one-wayoutlet valve 1036 and biasing member 1038. One-way outlet valve sealsagainst valve seat 1037. One-way outlet valve 1036 may be any type ofone-way valve such as, for example, a ball and spring valve, a poppetvalve, a flap valve, an umbrella valve, a slit valve or the like. Inaddition, insert 1073 contains a sanitary seal 1060. Sanitary seal 1060is a flexible member that forms a one-way valve that allows air to enterfrom passageway 1042 and into the upper portion of cavity 1039 butprevents liquid or foam from flowing back into passageway 1042. In oneembodiment, sanitary valve 1060 is integrally formed with insert 1073.Sanitary valve 1060 is a sanitary valve because it prevents liquid andfoam from traveling into components of the foam dispenser that are notdiscarded with the refill unit that includes pump 1000. Insert 1073includes foaming media 1070 secured therein. Foaming media 1070 may beone or more screens, porous members, baffles, a sponge, a foamingcartridge, or the like. Foaming media 1070 may be an integral part withinsert 1073 or may be a separate part.

An exemplary benefit to using sleeve 1020 is that the liquid inletand/or inlet valve 1010 may be positioned over any portion of the sleevewithout affecting the volume of liquid chamber 1012 or reducing theefficiency of pump 1000. Similarly, the liquid outlet and/or liquidoutlet valve 1036 may be located along any portion of the sleeve withoutreducing the volume of liquid chamber 1012 or reducing the efficiency ofpump 1000. In some embodiments, the liquid inlet and the liquid outletare offset from one another. In some embodiments, the liquid outlet islocated closer to the front of a dispenser than the liquid inlet whenthe pump 1000 is installed in the foam pump. In some embodiments, theliquid inlet and liquid outlet are along a common axis. The liquidpiston 1027 may moved along a pump axis that is substantiallyhorizontal. In some embodiments, the liquid inlet valve 1010 moves alongan axis that is substantially normal to the pump axis. In someembodiments, a portion of the liquid inlet valve 1010 moves along asubstantial vertical axis, such as the inlet valve 1010 illustrated inFIGS. 10 and 11, which may collapse both horizontally and vertically.

In addition, although the pump 1000 has been described as being made ofselected sub-parts, pump 1000, as well as the other embodiments of pumpsdisclosed herein, may be made from more sub-parts or fewer sub-parts.

FIG. 10 illustrates pump 1000 in a fully discharged position. FIG. 11illustrates pump 1000 in a charged or primed state. During operation, aspiston 1027 of pump 1000 moves from the discharged position illustratedin FIG. 10 to the charged or primed state illustrated in FIG. 11, liquidflows in through liquid inlets 1009 into liquid chamber 1012 and throughpassageways 1022, 1024 into the interior of sleeve 1020. Simultaneously,bellows 1054 moves from a contracted position to an expanded position.Movement of bellows 1054 to an expanded position draws air in throughthe outlet 1074 and sucks back any residual fluid and foam to preventfluid from leaking out of the outlet 1074 after the dispense cycle.

Movement of piston 1074 from the charged position illustrated in FIG. 11to the discharged position illustrated in FIG. 10 causes fluid to flowout of the liquid chamber 1012 (including the center of the sleeve 1020)through passageways 1028, 1026 past liquid outlet valve 1036 into mixingchamber 1046. Simultaneously, bellows 1054 is collapsed forcing anyliquid drawn in during the “suck back” operation into cavity 1039. Inaddition, air from an air source (not shown) flows through air passage1042, through aperture 1044, past sanitary valve 1060, up around the topof member 1075 and into mixing chamber 1046 where it mixes with theincoming liquid. The air and liquid mixture is forced through aperture1062 and through foam media 1070 to create a rich foam. The rich foamtravels through tapered section 1072 where it accelerates due to thereduced volume and exits foam pump 1000 through outlet 1074.

FIG. 12 illustrates yet another exemplary embodiment of a horizontalpump 1200. As with all the exemplary pumps disclosed herein, pump 1200may be used with many different types of the containers or dispensersincluding the ones disclosed herein. Pump 1200 includes a housing 1202.Housing 1202 includes annular projection 1203 that together with theupper portion of housing 1202 forms an annular groove 1203A thatreceives a container (not shown). Pump 1200 may be connected to thecontainer by any means such as, for example, a threaded connection, anadhesive connection, a friction fit, a welded connection or the like. Inaddition, a gasket (not shown) may be used to create a liquid tight sealbetween a container and pump 1200.

Housing 1202 includes an aperture 1204 through the housing 1202 intopump chamber 1220. In addition, one or more liquid inlet apertures 1208are included through housing 1202. A one-way check valve 1206 allowsfluid to enter pump chamber 1220 from a container (not shown) andprevents fluid from exiting pump chamber 1220 and flowing back into thecontainer. One-way check valve 1206 includes a stem 1207. Stem 1207 hasa projecting member 1209 located at one end. Projecting member 1209 maybe a spherical projection as shown, or may be a projection with a lowerprofile. Projection 1209 is pushed through aperture 1204 and expandsonce it passes through the aperture 1204 to retain one-way valve 1206 inplace. Optionally, a second projecting member 1210 is also located alongthe stem 1207. Second projecting member 1210 contacts a surface ofhousing 1202 and also helps to keep one-way valve 1206 in place. One-wayvalve 1206 includes sealing member 1211. Sealing member 1211 has aconical shape and is resilient. In one embodiment, one-way valve 1206 isformed of a unitary resilient piece. During operation, sealing member1211 is configured to deflect to allow liquid under pressure to passfrom a container into the pump chamber 1220. When liquid chamber 1220 ispressurized, sealing member 1211 contacts surface 1205 of annularprojection 1203 and forms a seal preventing liquid from flowing frompump chamber 1220 past sealing member 1211.

A unique feature about one-way liquid inlet valve 1206 is that one-wayliquid inlet valve 1206 may be secured to pump housing 1202 from outsideof the pump. Current liquid inlet valves are connected to the pumphousing from the inside the pump housing. In addition, the arrangementshown and described herein of having the sealing member 1211 of theone-way liquid inlet valve located above the liquid inlet apertures 1208and outside of the pump chamber 1220 is advantageous in that the portionof one-way valve 1206 located inside of the pump chamber 1220 may bereduced.

Optionally, other types of one-way check valves may be used such as, forexample, a flap valve, a poppet valve, an umbrella valve, a spring andball valve or any other valve that allows fluid to flow into pumpchamber 1220 and prevents fluid from flowing from the pump chamber 1220back into the container (not shown). However, these valves would besecured to the pump housing from inside the pump housing.

Located at least partially within pump chamber 1220 is a sleeve 1230.Sleeve 1230 fits within pump chamber 1220 and creates one or morepassageways between the outside wall of the sleeve 1230 and one or morewalls of the pump chamber 1220. The passageways may be similar to thosedescribed with respect to the pumps disclosed in FIGS. 3, 4, 10 and 11.Sleeve 1230 is secured to housing 1202 by a collar or end cap 1231.Collar 1231 may be press-fit into housing 1202, secured with anadhesive, connected by a threaded connection, or the like.

A piston head 1236 is secured to piston rod 1234 and is movable in areciprocating fashion within sleeve 1230 to expand and contract the pumpchamber 1220. As discussed above in more detail, benefits to having thesleeve 1230 is that the inlet to the pump chamber 1220 and the outletfrom the pump chamber 1220 may be located anywhere along the length ofthe pump chamber 1220, or sleeve 1230. For example, in some embodiments,the liquid inlet and liquid outlet are offset from one another. In oneembodiment, the liquid outlet is located farther away from the back of adispenser when the pump 1220 is used in a dispenser. Although they areonly off-set slightly in the embodiment illustrated in FIG. 12, thecenter of the liquid inlet valve being off-sett from the center of theliquid outlet valve. In some embodiments, the center of the valves arewell off-set.

Housing 1202 includes a cavity 1270. A portion of cavity 1270 formsmixing chamber 1214. An air inlet 1212 is located in a side wall of thecavity 1270. An annular projection 1262 extends outward and surroundsair inlet 1212. Annular projection 1262 forms a means for connectingpump 1200 with an air source (not shown) for providing air to pump 1200to mix with the liquid to form a foam. The air source may be an aircompressor permanently attached to the pump 1200 or may be an air sourcethat is releasably connected to pump 1200. The air source may be apositive displacement air pump, a bellows pump, a piston pump, a fan, anair compressor, or the like.

Located within cavity 1270 is dual action valve 1240. Dual action valve1240 has a first wiper seal 1242 and a second wiper seal 1244, both ofwhich are flexible. The first and second wiper seals 1242, 1244 alsoform part of the mixing chamber 1214, which is located between them.First wiper seal 1242 is a one-way liquid inlet valve which allowsliquid under pressure to enter mixing chamber 1214. Second wiper seal1244 is a one-way air inlet valve that allows air to enter mixingchamber 1214 and prevents liquid or air from traveling from the mixingchamber 1214 back toward the air source (not shown). Dual action valve1240 includes an internal passage 1241. An aperture 1246 through thewall of the dual action valve 1240 allows the mixture of liquid and airto travel from the mixing chamber into passage 1241. The lower end ofdual action valve 1240 has a flared portion 1245 proximate the outlet1256. In addition, dual action valve 1240 includes an annular projectionmember 1260. Annular projection member 1260 is secured to the surface1248 of housing 1202. Annular projection member 1260 may be secured tosurface 1248 with an adhesive, a friction fit, a welded connection orthe like. In one embodiment, dual action valve 1240 is a single piececonstruction. In some embodiments, one or more of the components of thedual action valve 1240 may be separate parts.

A foaming cartridge 1250 fits within the flared portion 1245 of dualaction valve 1240. In one embodiment, foaming cartridge 1250 includesscreens 1252. Screens 1252 may be individually secured in the flaredportion 1245 without being connected to a cartridge. Optionally, foamingcartridge 1250 may simply be a porous member or a series of baffles.

During operation, piston head 1234 is moved outward toward the front ofpump chamber 1220 which expands pump chamber 1220 creating a vacuumwhich causes one-way liquid outlet valve 1242 to seal against surface1243. Liquid flows from the container (not shown) and into pump chamber1220 past one-way liquid inlet valve 1206. The fluid flows around sleeve1230 along channels 1221 and 1222 and into the interior of the sleeve1230.

As the piston head 1234 moves inward toward the back of pump chamber1220, the volume of pump chamber 1220 is reduced. The pressure createdby the contracting pump chamber 1220 forces one-way liquid inlet valve1206 to close by sealing off against surface 1205. Liquid travels pastwiper seal 1242 into mixing chamber 1214. Air travels from an air source(not shown) that connects to member 1262 through aperture 1212 intocavity 1270 past wiper seal 1244 and into mixing chamber 1214 where theair mixes with the liquid to form an air/liquid mixture. The liquid andair may simultaneously enter mixing chamber 1214. Optionally, the timingmay be slightly offset, wherein liquid starts entering the chamberslightly prior to the air, or in one embodiment, the liquid entersmixing chamber prior to the air entering the mixing chamber. Theliquid/air mixture is forced by the air pressure through aperture 1246into passage 1241, through foaming cartridge 1250 and is dispensed outof outlet nozzle 1256 as a foam.

The air compressors and liquid pumps described herein may includebiasing members to return them to a first state, or a charged state.Optionally, a biasing member in one or more of the air compressors orliquid pumps may return other air compressors and/or liquid pumps to afirst state. In some embodiments, a biasing member in the actuatormechanism returns the air compressor and/or liquid pumps to a firststate. Still yet, if the air compressor and or liquid pump areelectrically operated, they may be moved to the first stateelectrically.

In addition, parts described with respect to one embodiment may becombined with parts described with respect to other embodiments. Forexample, the “suck back” feature described with respect to pump 1000 maybe incorporated into any of the other pumps, refill units or dispensers.

While the present invention has been illustrated by the description ofembodiments thereof and while the embodiments have been described inconsiderable detail, it is not the intention of the applicants torestrict or in any way limit the scope of the appended claims to suchdetail. Additional advantages and modifications will readily appear tothose skilled in the art. Moreover, elements described with oneembodiment may be readily adapted for use with other embodiments.Therefore, the invention, in its broader aspects, is not limited to thespecific details, the representative apparatus and/or illustrativeexamples shown and described. Accordingly, departures may be made fromsuch details without departing from the spirit or scope of theapplicants' general inventive concept.

We claim:
 1. A disposable refill unit for a foam dispenser that has anintegral air compressor comprising; a container; a liquid pump securedto the container; the liquid pump having a liquid chamber defined atleast in part by a liquid inlet valve and a liquid outlet valve; aliquid piston that reciprocates horizontally in the liquid chamber; amixing chamber located downstream of the liquid chamber; an air inlet influid communication with the mixing chamber; a sanitary seal locatedproximate the air inlet, the sanitary seal allows air to enter themixing chamber and prevents liquid from exiting the mixing chamberthrough the air inlet.
 2. The disposable refill unit of claim 1 furthercomprising a sleeve located at least partially within the liquid chamberand at least a portion of the liquid piston reciprocates within thesleeve.
 3. The disposable refill unit of claim 2 further comprising oneor more ribs located on the sleeve or on one or more walls of the liquidchamber.
 4. The disposable refill unit of claim 1 wherein the liquidinlet valve and the liquid outlet valve are offset from one another. 5.The disposable refill unit of claim 1 wherein the liquid outlet valve islocated closer to the front of the disposable refill unit than theliquid inlet valve.
 6. The disposable refill unit of claim 1 furthercomprising a connector for connecting the liquid pump air inlet to anair outlet of an air compressor.
 7. The disposable refill unit of claim1 wherein the refill unit is configured to be lowered into a dispenseralong a vertical axis.
 8. The disposable refill unit of claim 1 whereinthe liquid pump further comprises one or more sealing members that format least a part of a channel for delivering air to the air inlet whenthe refill unit is installed in a foam dispenser.
 9. The disposablerefill unit of claim 1 wherein the liquid piston is movable to aplurality of positions within the liquid chamber and a head of thepiston is located on one side of the outlet valve when the piston is ina first position and the head of the piston is located on the oppositeside of the outlet valve when the piston is in a second position. 10.The disposable refill unit of claim 1 further comprising a suck backchamber in fluid communication with the mixing chamber.
 11. A disposablerefill unit for a foam dispenser that has an integral air compressorcomprising; a container; a liquid pump secured to the container; theliquid pump having a liquid chamber defined at least in part by a liquidinlet valve and a liquid outlet valve; a mixing chamber locateddownstream of the liquid chamber; an air inlet in fluid communicationwith the mixing chamber; a sanitary seal located proximate the airinlet, the sanitary seal allows air to enter the mixing chamber andprevents liquid from exiting the mixing chamber through the air inlet;wherein the container, the liquid pump and the sanitary seal aredisposable.
 12. The disposable refill unit of claim 11 wherein theliquid inlet valve and the liquid outlet valve are offset from oneanother.
 13. The disposable refill unit of claim 11 wherein the liquidoutlet valve is located closer to the front of the refill unit than theliquid inlet valve.
 14. The disposable refill unit of claim 11 whereinat least one of the inlet valve and outlet valve are located off of acenter line of the container.
 15. The disposable refill unit of claim 11wherein the liquid pump comprises one or more sealing members, whereinwhen the disposable refill unit is installed in a foam dispenser, theone or more sealing members form at least a portion of an airpassageway.
 16. The disposable refill unit of claim 11 furthercomprising a suck back chamber in fluid communication with the mixingchamber
 17. A disposable refill unit comprising: a container of foamableliquid; a pump secured to the container; the pump having a pump housing;an aperture through an upper surface of the pump housing; a liquid inletvalve; the liquid inlet valve including a stem portion; the stem portionhaving a projection member; the liquid inlet valve including a sealingmember; a pump chamber located within the pump housing, wherein theaperture extends from the upper surface of the pump housing to the pumpchamber; wherein the projection member of the liquid inlet valve stem islocated at least partially within the pump chamber and the sealingmember of the liquid inlet valve is located above the upper surface ofthe pump housing; and one or more liquid inlet passages located in thehousing between the upper surface and the pump chamber; wherein thesealing member is located upstream of the one or more liquid inletpassages.
 18. A disposable refill unit for a foam dispenser that has anintegral air compressor comprising; a container for holding a foamableliquid; a liquid pump secured to the container; the liquid pump having aliquid chamber defined at least in part by a liquid inlet valve and aliquid outlet valve; a sleeve located at least partially within theliquid chamber; a liquid piston that reciprocates horizontally in theliquid chamber and in contact with the sleeve; a mixing chamber locateddownstream of the liquid chamber; an air inlet in fluid communicationwith the mixing chamber; wherein the center of the liquid outlet valveis off-set from the center of the liquid inlet valve.
 19. The disposablerefill unit of claim 18 further comprising a member having a first wipervalve oriented in a first direction and a second wiper valve oriented ins second direction that is different then the first direction andwherein the first wiper valve is the liquid outlet valve and the secondwiper valve is an air inlet valve.
 20. The disposable refill unit ofclaim 19 wherein the movement of the piston is substantially normal thedirection of the fluid flow.